Minimally invasive cardiac surgery entails the performance of heart surgery through very small incisions. Due to the limited size of the incisions, the patient's heart is not completely exposed. To assure a good or stable heart rhythm during and or after heart surgery, temporary pacing wires, which electrically stimulate the heart, are often sewn to the heart surface, and are used until patient self-pacing is achieved. This can be very difficult to do in some types of minimally invasive cardiac surgery cases without increasing the amount of heart dissection that is done, or increasing the risk of bleeding due to wire placement.
Minimally invasive cardiac surgery is known to utilize catheters that are placed into and along the patient's vasculature to allow safe initiation of cardiopulmonary bypass through catheters via small incisions. During cardiopulmonary bypass, blood is removed from the patient's pulmonary artery and the heart is stopped. The aspirated blood is then oxygenated by a medical apparatus and is then returned to the patient's arterial system at an appropriate location spaced from the heart, such as into a peripheral artery. Once the patient's heart function is undertaken by the cardiopulmonary bypass machine, the surgery can be safely performed through small incisions. The bypass procedure generally utilizes, along with several other catheters, a pulmonary venting (draining) catheter that is placed into and through the vasculature, preferably the jugular vein and superior vena cava, into and through the heart's right atrium and right ventricle, and into the pulmonary artery. The catheter distal end is then left in the pulmonary artery so that drainage of blood is by way of the distally open intake lumen of the catheter. One such pulmonary venting catheter is the ENDOVENT® catheter manufactured by Edwards Lifesciences Corp. (Irvine, Calif.).
It is known to provide a pacing wire into a patient where the distal wire end does not require sewing the tip to heart tissue. By use of a Swan-Ganz PACEPORT® pacing wire manufactured by Edwards Lifesciences Corp., a bipolar pacing wire is introduced into the patient's vasculature and the distal pacing wire end enters into the heart's right ventricle until it becomes engaged against the inner surface of the ventricle, termed intracardiac pacing. This catheter is utilized after pulmonary venting has been performed and after the venting catheter has been withdrawn from the patient. The bipolar pacing wire includes two conductive electrodes that are insulated from each other, one of which extends to the distal wire end, while the other concludes proximally of the distal wire end and is exposed to engage nearby right ventricle tissue. The distal wire end portion is so made to be extremely flexible so as not to damage the heart (or other) tissue of the patient, whereby a length of the distal end portion lies along and against the heart surface for best results. Such intracardiac pacing is performed during weaning from cardiopulmonary bypass, and also for post-operative management to improve cardiac output.
Generally, in the course of performing minimally invasive cardiac surgery without the use of pacing wires sewn to the patient's heart, the pulmonary vent must be exchanged with a pacing catheter that contains the pacing wire through the use of an introducing catheter. This requires a sterile technique with limited access to the head and neck of the patient during the procedure. Additionally, the heart may not have adequate flow or any native activity, making it a challenge to advance the pacing catheter into the right ventricle, and further out into the pulmonary artery. This may lead to numerous problems, including: the catheter being positioned in an incorrect location; the introducing catheter may become bent during the exchange, trapping the pacing catheter; or, the pacing catheter may loop, knot, perforate the heart, damage the heart valves, or become entangled in the chordae tendinae, etc.
It would be desirable to have a catheter assembly and a method of use of same that simplifies the minimally invasive cardiac surgery procedure, reduces the total time needed therefor in patients, and eliminates the need for additional heart surface stitches, among other desirable features, as described herein.